Log debarking machine



June 15, 1965 Filed April 23, 1962 P. G. BRUNDELL ETAL LOG DEBARKINGMACHINE 3 Sheets-Sheet 1 June 15, 1965 P. G.IBRUNDELL ETAL 3,139,058

LOG DEBARKING MACHINE Filed April 23, 1962 3 Sheets-Sheet 2 Fig.2

June 15, 1965 P. s. BRUNDELL ETAL LOG- DEBARKING MACHINE 3 Sheets-Sheet5 Filed April 23, 1962 3 s s 7 2 f M 6 3 k a +4 3 4 4 v i. 7 up Ilsl 4III-I1 mi h I $1 ORN United States Patent O 3,189,068 LOG DEBARKINGMACHINE Per Gunnar llrundell, Toltfors, Gayle, and Karl-Erik Arnold.lionsson, Ga le, Sweden, assignors to Siiderhainns Verlrstiider AB,Soderhamn, Sweden, a corporation of Sweden Filed Apr. 23,1962, Ser. No.189,466 Claims priority, application Sweden May 10, 1961,

4,940/61 Claims. (Cl. 144-208) The invention relates to a debarkingmachine of the type in which a hollow rotor provided with debarkingtools is carried by a housing which is hingedly suspended on a shaftdirected in parallel to the axis of the rotor. Conveyor means arelocated at both ends of the rotor to move logs through it, and thehousing is adapted to be adjusted in dependence on the diameter of thelogs so as to place the rotor coaxially in alignment with a log to beintroduced. Further, a rotatable roll above the conveyor at each end ofthe rotor is movable in vertical direction to exert a downward holdingpressure on the logs moving through the rotor.

Debarking machines of this kind are primarily of interest in debarkingthick and unassorted logs, some of which are even so thick that theycannot pass the rotor. In such case, the pivotally suspended rotor canbe moved aside, to let the too thick logs pass along the conveyorwithout being debarked. A drawback with this arrangement is, however,that said log-engaging rolls must simultaneously be raised separately soas not to obstruct the passage of the logs.

The object of the invention is to provide an improved debarking machineeliminating this drawback. According to the invention, each of saidrolls is carried by an arm hingedly supported in the housing to berotated in a vertical plane substantially perpendicular to the axis -ofthe rotor, and power transmitting means are mounted on the housing torotate the arms a desired angle to lift the rolls onto a log. By thisdevice, the log-engaging rolls are automatically moved aside togetherwith the rotor so that thicker logs are not prevented from passing. As

the pivots of the roll-carrying arms are moved together with thehousing, the pivotal movement of said arms on the pivots will be limitedto a smaller angle than would be the case if the pivots of the arms werecarried by a stationary support. By means of simple mechanisms it is,moreover, possible to adjust the arms automatically in desired angularpositions independence on the pivotal movement of the housing. Accordingto a preferred embodiment described in detail hereinafter, it is alsopossible to cause the rolls to engage the log bythe action of at leastpart of the weight of the hingedly suspended machine, so that the weightof the rolls themselves and their arms need not be very great.

Further features of the debarking-machine according to the invention areapparent from the following description of a preferred embodiment shownin the accompanying drawings,

FIGURE 1 shows a side elevation of the machine as seen from the inletend, whereas FIGURE 2 is a top plan view of the same machineL' FIGURE 3is a sectional view illustrating the central valve arrangement for thecylinder and piston unit connecting the feed roll arm to the rotorhousing.

The machine is built up on a rectangular frame 3 made of I-beams,Secured to one end of said frame is an upright support or bracket 4.Said support is composed of two vertical, laterally spaced side plate 5mounted in parallel to the longitudinal direction of the frame (FIG. 2)and a transverse end plate 6. joining said side plates. The rotor 7 andits tools 8 adapted to en- 3,189,9fi8 Patentedjune 15, 1965 gage thesurface of a log '9 introduced may be of any suitable construction. Insome known way, the rotor is journalled in a stator made integral with acylinder ltl enclosing the rotor periphery, Along approximately half itsperiphery the cylinder 10 is secured to a box-shaped housing 11pivotally suspended in the support 4 by means of a pivot 12. The housingis adjustable in the desired angular position in relation to the frame 3by means of a hydraulic cylinder 13. One end of this cylinder is linkedto the frame 3 below the support 4, while the projecting end of thepiston rod is linked to a lug 14 provided on the bottom of the housing11. The supply of pressure fluid to the cylinder 13 is controlled by avalve operated manually.

,The rotor'7 is driven by a motor 15 secured to one side of the housing11. Though not shown, the driving pulley of the motor is disposed withinthe housing, and the cylindrical wall 10 isprovided with openingsrequired for the passage of driving belts.

Outside each end of the rotor the cylinder 10 carries a protectiveshield 16 and 17, respectively. The shield 16 at the outlet end isannular, while the shield 17 at the inlet end (visible in FIG. 1)extends only along a little more than half the circumference of therotor. A feed roll 18 fixed to a horizontal shaft 19 is disposedopposite the rotor outside each shield. Each roll 18 may be regarded ascomposed of two truncated cones turning their narrower ends towards eachother, and the envelope surface of the roll is provided with groovesdirected axial- 1y or at oblique angles to the axis. The shaft 19 isjournalled in bearings 20 [and 21 carried by supports 22 and 23,respectively, secured to the frame 3. A sprocket 24 is fixed to oneendof each shaft 19, and both sprockets 24 are driven by a sprocket wheel25 on a shaft extending from a gear box 27 coupled to a motor 26.Thoughnot shown, a conveyor is arranged for advancing the logs to theroll 18 in front of the rotor and another conveyor receives debarkedlogs from the roll disposed behind the rotor.

A roll 28 concave in profile and provided with peripheral grooves islocated above each of the feed r0lls18 to engage the logs from above soas to retain them in correct position during the passage through therotor. Each roll 28 is journalled at the free end of an arm 29 hingedlymounted on the housing to rotate in a vertical plane substantiallyperpendicularto the axis of the rotor. In the embodiment shown (FIG. 2),the two arms 29 are secured to a common shaft 30 journalled in thehousing 11in parallel to the pivot 12. Preferably the shaft 30 islocated at apoint above a center line A connecting the center of thepivot 12 with the center of the rotor, FIG. 1. One end of a hydrauliccylinder 31 is linked to a lug32 provided on one of the arms 29, and thepiston rod 33 projecting from the opposite end of the cylinder is linkedto a pivot 34 secured in the lower part of the' housing 11. A valve 35is secured to the cylinder 31, and a movable valve reversing member 36is connected to one end ofa Bowden cable 42 mounted in a U-shaped sleeve37 on the housing'll. The other end of the cable is by means of ahelical spring 3 8 kept incontact with the upper surface of one of thebeams of the frame 3. The valve 35 controls conduits, see FIGURE 3, forsupplying pressure fiuid to theends of the cylinder 31. Preferably saidvalve isof a type used in connection with hydraulic normal neutralposition because of the upward movement of the cylinder.

FIGURE 3 shows the cylinder 31 and the valve mechanism 35 in section.The valve housing 35 contains a valve slide 41 which is secured to theBowden cable 42. In the known manner, the cable 42 is encased by aflexible sleeve 37. The valve housing has a central inlet port 43 andtwo outlet ports 4-4 and &5, one at each end. Two pistons 46 and 47 onthe valve slide 41 are adapted to cooperate each with one port 43 and49, respectively. The two ports 43 and 4-9 are by means of passages 50and 51, respectively, connected each to one end of the cylinder 31.

'In FIG. 3, the piston 52 of the cylinder 31 is in its central positionand the two valve slide pistons 46, 47 close the ports 48 and 4-9,respectively. Should the rot-or housing 11 be swung upwards, i.e.clockwise in FIG. 1,-the outer end of the cable 4-2 will be pushed outby the spring 33 to keep in contact with the beam 3, and thereby thevalve slide 41 is pulled upwards. The cylinder space above the piston 52is thereby brought into communication with the inlet 43 which isconnected to a source of pressure fluid. The piston 52 will be depressedand the arms 29 are caused to swing upwards on the pivot 30. At thisupward movement of the arms the slide 41 is returned into the closingposition in FIG. 3, and the piston 52 is then held in its new positionwithin the cylinder.

When the housing 11 moves downwards, also the valve member is moveddownwards and supplies fluid to the lower end of the cylinder so thatthe rolls 28 are lowered. The automatic control of the arms 29 describedis no necessary condition, as instead the cylinder 31 may very well beactuated by means of a valve operated manually.

A structural detail not mentioned previously is a pcripheral fin 39 onthe cylinder wall remote from the housing 11. Said fin 39 is arranged toengage a groove in an arcuate upright guide member 40 fixed to the frame3, and the object of this device is to absorb some of the thrust towhich the housing 11 is subjected when a log is fed through the rotor.

In FIG. 1, the log 9 shown has the smallest diameter that can bede'oarked in the machine and consequently the rotor 7 is in its lowestposition, while at the same time the piston rod of the cylinder 13 isentirely retracted. The maximum log diameter is only slightly smallerthan the inner diameter of the rotor, and to receive such a log therotor must be raised such that the lower part of its inner surface isapproximately on a level with the top of the feed roll 18. Between thisposition and the position shown in FIG. 1 the center of the rotor movesalong an are having the pivot 12 as its center. Thus, it is not to beavoided that the center of the rotor is displaced slightly in a lateraldirection in relation to the roll 18, i.e. to the left in FIG. 1.Particularly when introducing very thick logs, however, it may besuitable to avoid a great lateral displacement, and for this reason thechord of said are is preferably directed almost vertically. In otherwords, the line connecting the center of the rotor to the center of thepivot 12 forms approximately the same angle to the horizontal planethrough the pivot center in the lowest as well as in the highestposition of the rotor. The lateral displacement of the rotor is alsocounteracted by the great distance between the pivot .12 and the rotorcenter, but in this respect the possibilities are of course limited forpractical reasons.

When the housing 11 is moved upwards, the log-engaging rolls 28 areraised simultaneously with and to the same extent as the rotor, as theirpivot shaft is journ-alled in the housing. To receive a bigger log,however, the rolls 28 must be raised twice as high the the rotor, andthis is taken care of by the cylinder 31. The valve and actuating means37 are dimensioned and mounted such that the rolls 28 move automaticallyto the level required for engaging the log surface. Because the shaft 30is mounted in the housing 11 the pivotal movement of the arms 29 isdecreased, and thereby the rolls 28 do not engage the log at too greatan angle even in case the log a maximum diameter. For the same purposethe shaft 39 is, as described, preferably disposed above the lineconnecting the center of the rotor to the pivot 12 so that the arms 29will slope downwards in the lower position of the rotor.

When the rotor 7 has been raised sufiiciently to receive a centered log,and the roll 28 before the inlet end of the rotor has engaged the logsurface, the pressure in the hydraulic cylinder 13 may be relievedentirely or preferably only partly by means of a known hydraulic valvemechanism (a so-called overflow valve) so that the two rolls 28 retainthe rotor in its position by resting on the log surface. In this way therolls 28 engage the log at an increased pressure which may be desired insome cases.

According to another embodiment the two arms 29 of the rolls may insteadbe arranged to move individually, either by being secured each to onepivot or by being journalled on a common shaft secured to the housing.In such case the two arms must of course be connected to separatelifting means.

The invention is not limited to the embodiment shown in the drawing. Forinstance, the arms 29 may instead be journalled in a part of the housingprojecting on the opposite side of the rotor in relation to the pivot1-2. According to a further embodiment said pivot may be disposed suchthat the central line corresponding to center line A of FIG. 1 isvertical or almost vertical in an initial position corresponding toFIG. 1. Such an arrangement is possible, if the shafts of the feed rolls18 are mounted at an angle to the horizontal plane.

What we claim is:

1. A debarking machine comprising a hollow rotor provided with debarkingtools to remove bark from logs fed through it, a housing carrying therotor and hingedly suspended on a shaft directed in parallel to the axisof the rotor, a motor mounted on the housing for rotating the rotor,conveyor means located at both ends of the rotor to move logs throughit, the housing being adapted to be adjusted about said shaft independence on the diameter of the logs so as to place the rotorcoaxially in alignment with a log to be introduced, means formaintaining the housing in adjusted position, a roll rotatably mountedabove the conveyor at each end of the rotor and movable in verticaldirection to exert a downward holding pressure on the logs movingthrough the rotor, arms carrying said rolls and hingedly supported insaid housing to swing in vertical planes substantially perpendicular tothe axis of the rotor, and power transmitting means mounted on thehousing and connected to the arms to swing said arms relative to thehousing to move the arms through a desired angle to lift the rolls abovean oncoming log.

2. A debarking machine comprising a hollow rotor provided with debarkingtools to remove bark from logs fed through it, a housing carrying therotor and hingedly suspended on a shaft directed in parallel to the axisof the rotor, 21 motor mounted on the housing for rotating the rotor,conveyor means located at both ends of the rotor to move logs throughit, the housing being adapted to be adjusted about said shaft independence on the diameter of the logs so as to place the rotorcoaxially in alignment with a log to be introduced, means formaintaining the housing in adjusted position, a roll rotatably mountedabove the conveyor at each end of the rotor and movable in verticaldirection to exert a downward holding pressure on the logs movingthrough the rotor, arms carrying said rolls and hingedly supported insaid housing to swing in vertical planes substantially perpendicular tothe axis of the rotor, power transmitting means mounted on the housingand connected to the arm to swing said arms a desired angle to lift therolls above an oncoming log, and means sensing the angular position ofthe housing in relation to a stationary support, said sensing meansbeing arranged to control said power transmitting means in such a waythat said rolls are moved in relation to and in the same direction asthe housing.

3. A debarking machine comprising a hollow rotor provided with debarkingtools to remove barkfrom logs fed through it, a housing carrying therotor and hingedly suspended on a shaft directed in parallel to the axisof the rotor, a motor mounted on the housing for rotating the rotor,conveyor means located at both ends of the rotor to move logs throughit, the housing being adapted to be adjusted about said shaft independence on the diameter of the logs so as to place the rotorcoaxially in alignment with a log to be introduced, means formaintaining the housing in adjusted position, a roll rotatably mountedabove the conveyor at each end of the rotor and movable in verticaldirection to exert a downward holding pressure on the logs movingthrough the rotor, arms carrying said rolls, a common pivot journalledin said housing extending substantially parallel to the axis of therotor, said pivot being movable with said housing and supporting saidarms for swinging movement in vertical planes substantiallyperpendicular to the axis of the rotor and power transmitting meansmounted on the housing and connected to at least one of said arms andoperative to swing both of said arms a desired angle about said commonpivot relative to the axis of the rotor and independently of themovement of the housing about the axis of said shaft so as to lift bothrolls above an oncoming log.

4. A debarking machine comprising a hollow rotor provided with debarkingtools to remove bark from logs fed through it, a housing carrying therotor and hingedly suspended on a shaft directed in parallel to the axisof the rotor, a motor mounted on the housing for rotating the rotor,conveyor means located at both ends of the rotor to move logs throughit, the housing being adapated to be adjusted about said shaft independence on the diameter of the logs so as to place the rotorcoaxially in alignment with a log to be introduced, means formaintaining the housing in adjusted position, a roll rotatably mountedabove the conveyor at each end of the rotor and movable in verticaldirection to exert a downward holding pressure on the logs movingthrough the rotor, arms carrying said rolls and hingedly supported insaid housing to swing in vertical planes substantially perpendicular tothe axis of the rotor, hydraulic means mounted on the housing to swingsaid arms a desired angle to lift the rolls above an oncoming log, meanssensing the angular position of the housing in relation to a stationarysupport, and valve means controlled by said sensing means for supplyingpressure fluid to said hydraulic means in such a way that said rolls aremoved in relation to and in the same direction as the housing.

5. A debarking machine according to claim 1, in which each rol1-carryingarm is supported in the housing at a point located between the rotor andthe axis of the shaft that horizontally supports the housing.

References Cited by the Examiner UNITED STATES PATENTS 2,675,255 4/54Bloedel et a1.

2,749,952 6/56 League.

2,785,715 3/ 57 Brundell et a1.

2,855,010 10/ 58 Lefiler.

2,925,107 2/60 Fitzwater.

3,019,825 2/62 Herolf.

FOREIGN PATENTS 78 8,839 1/58 Great Britain.

LESTER M. SWINGLE, Primary Examiner.

EARL EMSHWI-LLER, WILLIAM W. DYER, IR.,

Examiners.

1. A DEBARKING MACHINE COMPRISING A HOLLOW ROTOR PROVIDED WITH DEBARKINGTOOL TO REMOVE BARK FROM LOGS FED THROUGH IT, A HOUSING CARRYING THEROTOR AND HINGEDLY SUSPENDED ON A SHAFT DIRECTED IN PARALLEL TO THE AXISOF THE ROTOR, A MOTOR MOUNTED ON THE HOUSING FOR ROTATING THE ROTOR,CONVEYOR MEANS LOCATED AT BOTH ENDS OF THE ROTOR TO MOVE LOGS THROUGHIT, THE HOUSING BEING ADAPTED TO BE ADJUSTED ABOUT SAID SHAFT INDEPENDENCE ON THE DIAMETER OF THE LOGS SO AS TO PLACE THE ROTORCOAXIALLY IN ALIGNMENT WITH A LOG TO BE INTRODUCED, MEANS FORMAINTAINING THE HOUSING IN ADJUSTED POSITION, A ROLL ROTATABLY MOUNTEDABOVE THE CONVEYOR AT EACH END OF THE ROTOR AND MOVABLE IN VERTICALDIRECTION TO EXERT A DOWNWARD HOLDING PRESSURE ON THE LOGS MOVINGTHROUGH THE ROTOR, ARMS CARRYING SAID ROLLS AND HIGEDLY SUPPORTED INSAID HOUSING TO SWING IN VERTICAL PLANES SUBSTANTIALLY PERPENDICULAR TOTHE AXIS OF THE ROTOR, AND POWER TRANSMITTING MEANS MOUNTED ON THEHOUSING AND CONNECTED TO THE ARMS TO SWING SAID ARMS RELATIVE TO THEHOUSING TO MOVE THE ARMS THROUGH A DESIRED ANGLE TO LIFT THE ROLLS ABOVEAN ONCOMING LOG.